The present invention relates in particular to technology for improving data retrieval efficiency in a distributed file system.
In recent years, industries such as the manufacturing industry have introduced a variety of systems such as business systems, production planning systems, production administration systems, and physical distribution systems with the aim of improving the efficiency of the various areas of business. In each system, the most recent data required for performing the various tasks are stored as files in a database. The users of each system then conduct retrieval of the database from dedicated terminals belonging to each particular system in order to refer to the desired data.
However, often the various systems have been introduced independently, and the equipment configuration and operating methods vary between systems. As a result, problems arise in those cases where data is retrieved from files distributed over a plurality of systems, as a number of data retrieval must be conducted over a plurality of systems before the desired data can be found, meaning the retrieval operation can take considerable time.
The present invention takes into consideration the above problems, with an object of integrating existing file systems and providing an integrated retrieval system with improved data retrieval efficiency by introducing so-called agents into a distributed file system.
Furthermore, another object of the present invention is to distribute a medium recorded with the integrated retrieval program of the present invention, so that people who acquire the medium can easily establish an integrated retrieval system.
To achieve the aforementioned objects, as a first device for solving the problems, there is provided an integrated retrieval system in a distributed file system which comprises a plurality of data management devices for distributively storing and managing data files, a plurality of cyclic control devices provided in a one-to-one ratio with the data management devices, and an input/output device for performing the input of retrieval instructions to the data management devices and the output of retrieval results from the data management devices, wherein the cyclic control devices comprise; a retrieval completion judgment device for judging whether or not a retrieval has been completed based on the retrieval instruction and retrieval results, a determination device for determining the next data management device to be retrieved when the retrieval completion judgment device has judged that the current retrieval has not been completed, and a retrieval instruction transmission device for transmitting the retrieval instruction to the data management device determined by the determination device.
With such a construction, when a retrieval of a distributed file system is conducted, a retrieval instruction is input via the input/output device. When a retrieval instruction is input, the data retrieval is executed in a data management device. A cyclic control device then judges whether or not the retrieval is completed based on the retrieval instruction and the retrieval results. Then, if the retrieval is still incomplete, the next data management device to be retrieved is determined and the retrieval instruction is transmitted to this next data management device. Following this, the retrieval instruction is transferred between the cyclic control devices and the data management devices until either the retrieval is completed, or all the data management devices have been retrieved. That is, by conducting only one retrieval operation, the retrieval instruction is automatically transferred between the cyclic control devices and the data management devices until the retrieval for the desired data is completed. Consequently, the data retrieval efficiency in the distributed file systems can be improved.
Furthermore, the construction may have a cyclic management device which manages collectively the plurality of cyclic control devices, wherein the cyclic management device is equipped with a definition file registration device for registering a definition file which defines the next data management device to be retrieved in accordance with the retrieval results, and the determination device determines the next data management device to be retrieved based on a definition file duplicated from the definition file registration device and the retrieval results.
With such a construction, the next data management device to be retrieved is determined based on a definition file duplicated from the definition file registration device and the retrieval results. That is, definition files are managed centrally in the definition file registration device, and duplicated from here to the cyclic control devices. Consequently, in those cases where it is necessary to update a definition file due to an alteration of, or an enlargement or reduction in the scale of the retrieval object, only the definition files registered in the definition file registration device need to be updated. As a result, maintenance work is reduced, enabling a reduction in running costs.
Moreover, the construction may be such that a protocol conversion device is disposed between the data management device and the cyclic control device, for converting the protocol between the data management device and the cyclic control device.
With such a construction, protocol conversion between the data management device and the cyclic control device is carried out by the protocol conversion device. Consequently, when establishing the integrated retrieval system of the present invention by utilizing an existing data management device, it is only necessary to customize the protocol conversion device to match it with the existing data management device. As a result, the integrated retrieval system can be established quickly and at low cost.
As a second device for solving the problems, there is provided an integrated retrieval method in a distributed file system which comprises a plurality of data management processes for distributively storing and managing data files, a plurality of cyclic control processes provided in a one-to-one ratio with the data management processes, and an input/output process for performing the input of retrieval instructions to the data management processes and the output of retrieval results from the data management processes, wherein the cyclic control processes comprise a retrieval completion judgment process for judging whether or not a retrieval has been completed based on the retrieval instruction and retrieval results, a determination process for determining the next data management process to be retrieved when the retrieval completion judgment process has judged that the current retrieval has been completed, and a retrieval instruction transmission process for transmitting the retrieval instruction to the data management process determined by the determination process.
With such a construction, when a retrieval of a distributed file system is conducted, a retrieval instruction is input via the input/output process. When a retrieval instruction is input, the data retrieval is executed in a data management process. A cyclic control process then judges whether or not the retrieval is completed based on the retrieval instruction and the retrieval results. Then, if the retrieval is still incomplete, the next data management process to be retrieved is determined and the retrieval instruction is transmitted to this next data management process. Following this, the retrieval instruction is transferred between the cyclic control processes and the data management processes until either the retrieval is completed, or all the data management processes have been retrieved. That is, by conducting only one retrieval operation, the retrieval instruction is automatically transferred between the cyclic control processes and the data management processes until the retrieval for the desired data is completed. Consequently, the data retrieval efficiency in the distributed file system can be improved.
Furthermore, the construction may have a cyclic management process which manages collectively the plurality of cyclic control processes, wherein the cyclic management process is equipped with a definition file registration process for registering a definition file which defines the next data management process to be retrieved in accordance with the retrieval results, and the determination process determines the next data management process to be retrieved based on a definition file duplicated from the definition file registration process and the retrieval results.
With such a construction, the next data management process to be retrieved is determined based on a definition file duplicated from the definition file registration process and the retrieval results. That is, definition files are managed centrally in the definition file registration process, and duplicated from here to the cyclic control processes. Consequently, in those cases where it is necessary to update a definition file due to an alteration of, or an enlargement or reduction in the scale of the retrieval object, only the definition files registered in the definition file registration process need to be updated. As a result, maintenance work is reduced, enabling a reduction in running costs.
As a third device for solving the problems, there is provided a medium recorded with an integrated retrieval program in a distributed file system, in which the integrated retrieval program realizes a plurality of data management functions for distributively storing and managing data files, a plurality of cyclic control functions provided in a one-to-one ratio with the data management functions, and an input/output function for performing the input of retrieval instructions to the data management functions and the output of retrieval results from the data management functions, wherein the cyclic control functions comprise a program for realizing a retrieval completion judgment function for judging whether or not a retrieval has been completed based on the retrieval instruction and retrieval results, a determination function for determining the next data management function to be retrieved when the retrieval completion judgment function has judged that the current retrieval has not been completed, and a retrieval instruction transmission function for transmitting the retrieval instruction to the data management function determined by the determination function.
In this respect, the term xe2x80x9cmediumxe2x80x9d means any medium which allows reliable storage of various information and which also allows the reliable retrieval of information as it is needed; specifically media such as paper cards (punch cards), paper tapes, magnetic tapes, magnetic disks, magnetic drums, IC cards and CDROMs.
With such a construction, an integrated retrieval program for realizing the data management function, the cyclic control function and the input/output function is recorded on a medium. The cyclic control function comprises a program for realizing a retrieval completion judgment function, a determination function, and a retrieval instruction transmission function. Consequently, from a medium recorded with the programs for realizing the various functions, each of the various functions can be transferred to a typical electronic computer for example, enabling the easy establishment of an integrated retrieval system of the present invention.
Furthermore, the construction may have a cyclic management function which manages collectively the plurality of cyclic control functions, wherein the cyclic management function is equipped with a definition file registration function for registering a definition file which defines the next data management function to be retrieved in accordance with the retrieval results, and the determination function determines the next data management function to be retrieved based on a definition file duplicated from the definition file registration function and the retrieval results.
With such a construction, the next data management function to be retrieved is determined based on a definition file duplicated from the definition file registration function and the retrieval results. That is, definition files are managed centrally in the definition file registration function, and duplicated from here to the cyclic control functions. Consequently, in those cases where it is necessary to update a definition file due to an alteration of, or an enlargement or reduction in the scale of the retrieval object, only the definition files registered in the definition file registration function need to be updated. As a result, maintenance work is reduced, enabling a reduction in running costs.
As a fourth device for solving the problems, there is provided an integrated retrieval system in a distributed file system comprising a plurality of retrieval execution devices for receiving data retrieval instructions and executing data retrieval, a retrieval completion judgment device for judging, based on the results of the data retrieval, whether or not the data retrieval specified by the data retrieval instruction has been completed, and a retrieval instruction transmission device for transmitting the data retrieval instruction to another retrieval execution device when judged that the data retrieval specified by the data retrieval instruction is still incomplete.
With such a construction, when a data retrieval instruction is received, a data retrieval is executed by a retrieval execution device. Then, based on the results of the data retrieval, a judgment is made by the retrieval completion judgment device as to whether or not the data retrieval specified by the data retrieval instruction has been completed. If the judgment is made that the data retrieval specified by the data retrieval instruction is incomplete, the data retrieval instruction is transmitted to another retrieval execution device by the retrieval instruction transmission device. Subsequently, the data retrieval instruction is continuously transmitted to the other retrieval execution device until the data retrieval specified by the data retrieval instruction has been completed. Consequently, it is possible to improve the data retrieval efficiency of the distributed file system.
Furthermore, the construction may be such that in the case where the protocol of the other retrieval execution device differs from the protocol of the retrieval execution device, the other retrieval execution device is provided with a protocol conversion device for converting the data retrieval instruction transmitted by the retrieval instruction transmission device to the protocol of the other retrieval execution device.
With such a construction, even if the protocol of the other retrieval execution device differs from the protocol of the retrieval execution device that transmitted the data retrieval instruction, the transmitted data retrieval instruction is converted by the protocol conversion device to the protocol of the other retrieval execution device. Consequently, even in those cases where an existing distributed file system with different protocols is being used, the integrated retrieval system can be established quickly and at low cost.
As a fifth device for solving the problems, there is provided a medium recorded with an integrated retrieval program in a distributed file system, in which the integrated retrieval program realizes a plurality of retrieval execution functions for receiving data retrieval instructions and executing data retrieval, a retrieval completion judgment function for judging, based on the results of the data retrieval, whether or not the data retrieval specified by the data retrieval instruction has been completed, and a retrieval instruction transmission function for transmitting the data retrieval instruction to another retrieval execution function when judged that the data retrieval specified by the data retrieval instruction is still incomplete.
With such a construction, the integrated retrieval program for realizing the plurality of retrieval execution functions, the retrieval completion judgment function and the retrieval instruction transmission function is recorded on a medium. Consequently, from this medium each of the functions can be transferred to a typical electronic computer, enabling the easy establishment of an integrated retrieval system of the present invention.
Other objects and aspects of the present invention will become apparent from the following description of the embodiment given in conjunction with the appended drawings.